Could you please kindly advise if you know a suitable solution or software for this task?

I have already tried "Secured PDF" - not allow printing feature of Adobe Acrobat X Pro, but I tested myself and see that there are many third-party tools and online services can remove this printing restrictions very easily within minutes.

I have also tried Mobipocket Creator (publisher edition) to create an eBook with the "Content Encrypted" choice at the last step, but I can be copied easily which may lead to unauthorized changes or printing.

If someone really wants to copy it, they will. Even if it's the newest and most secure uncrackable DRM method, someone can print screen it, OCR it, style it and make a very close replica. Print screen is easier (and faster) than scanning a paper book. Granted, there aren't many people capable of doing this, but it only takes one. He/she uploads it to a public torrent tracker and if the book is worth it, it will spread like wild fire. Of course, if the book is worth it, a lot more people will buy it than steal it. So worrying about DRM is counter productive, in my opinion. You should be worrying about the content instead.

2-PRC or other friendly Kindle, iPad... format: I personally prefer these formats since they are popularly supported well on various kind of devices. But what is the difference between "no Encrypted" vs "Content Encrypted" of PRC file made with Mobipocket Creator. I personally could not find any differences between them?

2-PRC or other friendly Kindle, iPad... format: I personally prefer these formats since they are popularly supported well on various kind of devices. But what is the difference between "no Encrypted" vs "Content Encrypted" of PRC file made with Mobipocket Creator. I personally could not find any differences between them?

PDF won't sell and the restrictions you put in place can easily be removed.

Kindle only is a really poor idea. You should also be supporting ePub. If you use DRM, again, can be stripped in no time.

How many times do we have to say that DRM is a failure do we have to say it to you? All of the above ideas are just really bad ideas.

2-PRC or other friendly Kindle, iPad... format: I personally prefer these formats since they are popularly supported well on various kind of devices. But what is the difference between "no Encrypted" vs "Content Encrypted" of PRC file made with Mobipocket Creator. I personally could not find any differences between them?

1. Bad for ebook readers, and why prevent printing?
2. You can get retailers to add DRM, but it's pointless, since either tools are still available to strip the DRM (which is the current case), or it will encourage people to not buy your book but to find it on a pirate site where it won't have the irritating DRM.

To prevent piracy you must prevent anyone, anywhere, anytime from accessing your content without the restrictions you place on it. As has been mentioned, so long as your customers can actually read the text, it can be copied. Once copied, anyone can get a copy from a torrent or other distribution means.

Why (apart from innate honesty, which is much more prevalent than you seem to think) would anyone buy your DRM-restricted and/or inconvenient product, when they can get a DRM-free, easy-to-use version of the same product for free?

DRM is a losing proposition, as the record labels eventually figured out. Most publishers are just starting to understand this too. Be ahead of the pack - publish DRM-free.

We have a series of books that we want to share them as FREE distribution, not for commercial purpose. In the past the book was printed for free distribution, and the printed books could not meet the huge demand. And many queries regarding the books keep on sending to the distributor for the free book.

So we are on the way to find a good solution and type file to publish them as free eBooks which is more convenient. But at the same time, we do not want other people take this advantage and publish them as commercial printed books.

So we now understand that it is impossible for preventing printing. But now the question left is which TYPE FILE is popularly supported among device.

We have a series of books that we want to share them as FREE distribution, not for commercial purpose. In the past the book was printed for free distribution, and the printed books could not meet the huge demand. And many queries regarding the books keep on sending to the distributor for the free book.

So we are on the way to find a good solution and type file to publish them as free eBooks which is more convenient. But at the same time, we do not want other people take this advantage and publish them as commercial printed books.

So we now understand that it is impossible for preventing printing. But now the question left is which TYPE FILE is popularly supported among device.

ePub is also good but some low-tech device cannot open it.

Ah, I see. The only way you can prevent commercial re-distribution (in paper or eInk) is by prosecuting anyone who does that. Hopefully, the existence of a free electronic version will mean that no-one finds it profitable to do it.

I would advise producing

* a PDF version that's just a PDF version of the print document, with any illustrations reduced to 96dpi. This is the easiest to do. Don't forget that it doesn't need much in the way of margins.

* an ePub version. This will be useful to all non-Kindle owners, and you can easily produce it with Sigil

* a combined Mobi/KF8 kindle version. Unless you're doing really fancy layout in the ePub, you can generate this from the ePub using KindleGen, and then use the KindleStrip python script to make it a sensible size by stripping the copy of the source ePub from the final book. This combined format will work on any Kindle device or software, with newer ones using the more capable KF8 format, and older ones the mobi version.

Ah, I see. The only way you can prevent commercial re-distribution (in paper or eInk) is by prosecuting anyone who does that. Hopefully, the existence of a free electronic version will mean that no-one finds it profitable to do it.

I would advise producing

* a PDF version that's just a PDF version of the print document, with any illustrations reduced to 96dpi. This is the easiest to do. Don't forget that it doesn't need much in the way of margins.

* an ePub version. This will be useful to all non-Kindle owners, and you can easily produce it with Sigil

* a combined Mobi/KF8 kindle version. Unless you're doing really fancy layout in the ePub, you can generate this from the ePub using KindleGen, and then use the KindleStrip python script to make it a sensible size by stripping the copy of the source ePub from the final book. This combined format will work on any Kindle device or software, with newer ones using the more capable KF8 format, and older ones the mobi version.

I should clarify that for the Mobi/KF8 version the user doesn't have to choose which version to read from the combined edition. Old software only sees the old (mobi) version, and new software will automatically find and use the KF8 version in the file.

Also, although for people with ebook readers ePub or Kindle are by far the preferred formats, for the general population, who will be reading on a desktop or laptop computer, PDF is a very, very popular format.